In FIG. 1, a prior art torque converter 10 contains a cover 12, an impeller 14, a turbine 16, a stator 18, a lock-up clutch 20, and a damper 22. Torque converter 10 is driven by an engine connected with studs 24, 26. Impeller 14 is rigidly attached to cover 12. Turbine 16 is rigidly attached to a turbine hub 28 with, for example, rivets 30. Turbine hub 28 is non-rotatably attached to an output shaft 32 with, for example, spines 34. Turbine hub 28 centers turbine 16 around output shaft 32.
A piston 36 and a piston hub 38 of lock-up clutch 20 may move axially on an outer hub 40 of turbine hub 28 according to the controlled pressure difference between regions 42, 44 on either axial side of piston 36. When piston 36 is not contacting cover 12 at a surface 46, torque is transferred from the engine to output shaft 32 through the hydraulic fluid in torque converter 10. When piston 36 is contacting cover 12 at surface 46, torque is transferred from the engine to output shaft 32 through springs 48 in damper 22. U.S. Pat. No. 5,385,222 is hereby incorporated by reference herein.